TWI596621B - Radioactive cesium removing apparatus - Google Patents

Description

Radioactive cesium removal device Field of invention

The present invention relates to a radioactive cesium removal apparatus which is a device for removing radioactive cesium from wastes containing radioactive cesium, particularly organic waste such as sewage sludge and foliage.

Background of the invention

Various proposals and devices for removing radioactive material contamination from organic waste containing radioactive materials such as radioactive cesium have been proposed. For example, Patent Document 1 discloses that radioactive waste generated by nuclear fission in the form of a nitrate is dissolved by electromagnetic induction heating in a cooling container having a slit provided in an externally wound electric coil. Separation/recovery method for nucleus volatilization with long half-life.

Advanced technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open No. Hei 5-157897

Summary of invention

However, the accident at the nuclear power plant was generated in Japan. The problem to be solved is not described in the above-mentioned Patent Document 1, but is discharged to the outside world by the waste generated by the normal operation in the nuclear energy-related facility, and is discharged by the soil, the sewage sludge, or the earthquake-damaged waste wood. Decontamination treatment of ingested radioactive materials. In particular, since it is predicted that this type of radioactive waste will reach a large amount, it is not the proposal of a simple means for removing radioactive contamination, but how to provide a large and efficient volatilization of radioactive materials and reduce the cost of recovery. means.

Here, the present invention has been completed in view of the above-described problems. The object is to provide a device for removing radioactive cesium from a waste containing radioactive cesium at a lower energy.

In order to achieve the above object, the present invention provides a radioactive cesium removal apparatus characterized by comprising an organic material supply means for supplying organic matter contaminated with radioactive cesium from a kiln; and an inorganic material supply means for supplying radioactive cesium contamination from the kiln. The inorganic kiln; the rotary kiln, wherein the organic substance is co-fired with the inorganic substance; and the recovery device is used to recover the volatilized ruthenium in the rotary kiln.

Then, according to the present invention, the fuel cost can be reduced by supplying the organic matter contaminated with radioactive cesium from the kiln in place of being a part of the fuel. Further, since the radioactive cesium-contaminated organic matter and inorganic matter can be treated at a high temperature in the rotary kiln, the radioactive cesium can be reliably removed.

Further, since the organic matter is supplied from the kiln and passed through the vortex After the high temperature portion of the kiln is turned and burned, the crucible is reliably vaporized, and is removed by being transported to the kiln by the air flow. Further, generation of unburned carbon or carbon monoxide is suppressed, and odor components generated from sewage sludge or the like can be decomposed. As a result, an additional device for exhaust gas treatment can be omitted. Further, since the sensible heat caused by the combustion of the organic matter is effectively utilized by supplying the inorganic material from the kiln, the firing can be performed efficiently.

Here, the organic matter contaminated by radioactive cesium refers to the waters of sewage sludge, sewage sludge dry powder/carbide, purified water sludge, construction sludge, pruning leaves/weeding dry matter, earthquake-damaged waste wood, lakes and so on. In the case of grasses and the like in the bottom material, the inorganic substances contaminated by radioactive cesium refer to the water quality of the sewage slag, soil, municipal waste incineration ash, various sludge incineration ash, rubble, lakes and the like.

In the above-described apparatus for removing radioactive cesium, a dry pulverizing apparatus for drying and pulverizing the organic substance may be further provided before the radioactive cesium-contaminated organic substance is introduced into the rotary kiln. Thereby, the original heat loss can be made large, and it is difficult to use the water sludge or the like as an alternative fuel, and the radioactive cesium contained in the batteries can be surely treated.

In the above-described apparatus for removing radioactive cesium, a reformer for modifying the inorganic substance may be provided before the radioactive cesium-contaminated organic substance is introduced into the rotary kiln, and a dry pulverizer for drying and pulverizing the granule may be further provided. By the modification, it is possible to improve the rationality of the adhesion of the aqueous inorganic substance to the storage tank or the conveyor, and to facilitate the transportation of the dryer or the like disposed in the subsequent stage. Moreover, by drying it, it is no longer necessary to heat the water in the inorganic material in the rotary kiln, so that the fuel can be made The dosage is reduced. Further, as the amount of exhaust gas discharged from the rotary kiln is reduced, the exhaust gas treatment device such as a cooling tower, a cyclone, a dust collector, and a denitration tower can be made compact, and the equipment cost can be reduced. Further, by pulverization, since the quality of the radioactive cesium concentration of the inorganic substance can be made uniform, the radioactive cesium can be stably and reliably treated in the rotary kiln.

In the above apparatus for removing radioactive cesium, the recovery device may be a cooling tower and a dust collector; the cooling tower cools the exhaust of the rotary kiln; and the dust collector recovers dust in the exhaust of the cooling tower.

In the apparatus for removing radioactive cesium, a classifier for separating coarse dust in the exhaust gas of the cooling tower is provided in a front stage of the dust collector, and coarse dust separated by the classifier can be returned to the rotary kiln. . Thereby, only the fine dust containing a large amount of radioactive cesium is dust-collected, and the radioactive cesium can be recovered more efficiently.

In the radioactive cesium removal apparatus, when the radioactive cesium-contaminated organic substance is co-fired with the radioactive cesium-contaminated inorganic substance, a calcium source may be added to the rotary kiln. Thereby, the alkalinity of the burned material can be increased, and the generation of the liquid phase during the firing can be suppressed, and the radioactive cesium can be volatilized efficiently.

In the apparatus for removing radioactive cesium, a classifier may be provided for classifying a decontamination product generated by volatilization of radioactive cesium in the rotary kiln; and adding a mixer to the insoluble material for further use. Here, a person who mixes insoluble materials is added. Thereby, the decontamination product can be adjusted to be suitable for the particle size of the cement admixture and the geotechnical material, and the heavy metal can be prevented from being eluted from the decontamination product or the like, so that the decontamination can be effectively utilized. Product.

As described above, according to the present invention, it is possible to provide a device which is a device for removing radioactive cesium from a waste containing radioactive cesium at a lower energy.

1‧‧‧ Radioactive cesium removal device

2‧‧‧organic material drying and pulverizing device

3‧‧‧Inorganic modified dry pulverizing device

4‧‧‧Burning device

5‧‧‧Decontamination system

6‧‧‧Decontamination product classification device

21, 32‧‧‧ Dryer

22, 33‧‧‧ pulverizer

31‧‧‧Changer

41‧‧‧Rotary kiln

41a‧‧‧Inorganic input

41b‧‧‧burner

42‧‧‧Clinker cooler

51‧‧‧Cooling tower

51a‧‧‧Dispersion device

52‧‧‧Cyclone separator

53‧‧‧ bag filter

54‧‧‧Denitrification tower

55‧‧‧ chimney

61‧‧‧ classifier

62‧‧‧Insoluble metal addition mixer

A‧‧‧Reaction accelerator (calcium source)

B‧‧‧Change materials

C‧‧‧ coarse dust

F‧‧‧Micronized dust

F1‧‧‧ fossil fuel

O1, O2, O3‧‧‧ (containing radioactive cesium) organic matter

G1, G2, G3, G4, G5‧‧‧ exhaust

H‧‧‧Exhaust gas from clinker cooler

P1‧‧‧Clinker (decontamination product)

P2‧‧‧Decontamination products

P3‧‧‧Geotechnical materials, etc. (decontamination products)

Q‧‧‧Insoluble materials

S1, S2, S3, S4‧‧‧ (containing radioactive cesium) inorganic substances

T‧‧‧Changed material

Fig. 1 is a view showing the entire configuration of an embodiment of a radioactive cesium removal apparatus of the present invention.

Form for implementing the invention

Next, the form for carrying out the present invention will be described in detail with reference to FIG. 1 . In the following description, the radioactive cesium removal device of the present invention removes radioactive cesium from radioactive cesium-containing organic substances and inorganic substances, and the organic matter after decontamination is described as an example. And inorganic materials to produce decontamination products that can be used in cement mixed materials and geotechnical materials. Here, the term "radioactive quinone" refers to cesium 134 and cesium 137 which are radioisotopes of hydrazine.

Fig. 1 is a view showing an embodiment of a radioactive cesium removal apparatus according to the present invention. The removal apparatus 1 is basically constituted by an organic matter drying and pulverizing apparatus 2, an inorganic substance-modifying and drying pulverizing apparatus 3, and a firing apparatus 4. The decontamination exhaust treatment device 5 and the decontamination product classification device 6.

The organic material drying and pulverizing apparatus 2 is disposed in the front stage of the firing apparatus 4, and is provided for drying and pulverizing the received radioactive cesium-containing organic substance (hereinafter simply referred to as "organic substance") O1. dry The dryer 21 and the pulverizer 22 are constructed.

The dryer 21 is provided for drying the organic substance O1 from the viewpoint of thermal efficiency when the moisture content of the received organic substance O1 is high. The pulverizer 22 is disposed in the subsequent stage of the dryer 21, and is provided for pulverizing the organic substance O2 dried by the dryer 21 into a suitable one for blowing from the burner 41b in front of the kiln of the rotary kiln 41. size. Here, the organic substance O1 to be fed to the organic material drying and pulverizing apparatus 2 means that the water content, the harvested material, the weeding, the straw, etc., which are contained in the radioactive cesium, are various, and the water content and the shape are various. Therefore, either or both of the dryer 21 and the pulverizer 22 may be omitted when it is not necessary to improve the properties or the like. Further, a dry pulverizing apparatus having both drying and pulverizing functions can be provided.

The inorganic-modified dry pulverizing apparatus 3 is disposed in the front stage of the firing apparatus 4, and is provided for the purpose of modifying and drying the received radioactive cesium-containing inorganic substance (hereinafter simply referred to as "inorganic substance") S1. It is pulverized and is composed of a reformer 31, a dryer 32, and a pulverizer 33.

The reformer 31 is provided for the purpose of adding a modified material T to the inorganic substance S1 and modifying it when the received inorganic substance S1 is inferior to the storage tank or the conveyor. Thereby, it is easy to convey the dryer 32 etc. arrange|positioned in the back stage. In the case of the modified material T, quicklime, slaked lime, calcium carbonate, cement, or the like can be used, and one type of these groups can be used alone or two or more types can be used in combination. Among them, it is preferable to use quicklime from the point of improvement effect and cost.

The dryer 32 is disposed in the rear stage of the reformer 31, and is configured to In the case where the water content of the inorganic material S2 after the modification is high, the inorganic material S2 is dried from the viewpoint of the low heat input in the rotary kiln 41.

The pulverizer 33 is disposed in the subsequent stage of the dryer 32, and is provided for pulverizing the inorganic substance S3 dried by the dryer 32 to an appropriate size to uniformize the quality of the radioactive cesium concentration.

Here, the inorganic substance S1 to be fed into the inorganic substance-modifying and drying pulverizing apparatus 3 refers to a water-containing substance such as slag containing radioactive cesium, soil, various incineration ash, rubble, lake, etc., water content and shape, as described above. The traits are also diverse. Therefore, any one or all of the reformer 31, the dryer 32, and the pulverizer 33 may be omitted when it is not necessary to improve the properties or the like. Further, it is also possible to provide a device having any of the functions of modification, drying, and pulverization, or both.

The firing device 4 is provided for firing the organic material O3 which has been dried and pulverized by the organic material drying and pulverizing apparatus 2, and is composed of a rotary kiln 41 and a clinker cooler 42.

The rotary kiln 41 is provided with an inlet port 41a for supplying the inorganic substance S4 to the inside of the drying furnace, and the inorganic substance S4 is modified, dried, and pulverized by the inorganic substance modification drying and pulverizing apparatus 3, and a burner 41b is provided in front of the kiln. The fossil fuel F1 such as fine carbon and the organic substance O3 are ejected into the rotary kiln 41 to be fired.

The clinker cooler 42 is provided for the following use: the fired product discharged from the rotary kiln 41 is cooled by the introduced cooling air (atmosphere) to obtain the decontamination product P1. High temperature from the clinker cooler 42 The exhaust gas H is supplied to the dryer 21 of the organic material and the dryer 32 of the inorganic material, and can be used for drying the organic substance O1 and the inorganic substance S2.

The decontamination-type exhaust gas treatment device 5 is disposed in the subsequent stage of the firing device 4, and is configured by a cooling tower 51 that cools the exhaust gas G1 discharged from the rotary kiln 41, and a cyclone separator 52. The coarse dust C contained in the exhaust gas G2 of the cooling tower 51 is recovered; the bag filter 53 is a dust collector F collected by the exhaust gas G3 of the cyclone 52; and the denitration tower 54 is performed. The denitrator of the exhaust gas G4 of the bag filter 53.

The cooling tower 51 is provided for cooling the exhaust gas G1 of the rotary kiln 41, and recovers the radioactive cesium volatilized from the organic substance O3 and the inorganic substance S4 in a solid form. The cooling of the exhaust gas G1 is performed by spraying water from the water diffusing device 51a provided at the lower end portion of the cooling tower 51. Further, the water diffusing device 51a may have a function of allowing the volatilized crucible to adhere to the dust contained in the exhaust gas G1 in a solid form, and the installation position of the water diffusing device 51a is not limited to the cooling tower 51. The lower end. Further, cooling may be performed without introducing water, but cooling may be performed by introducing cooling air into the cooling tower; cooling by water and cooling by air may be used alone or in combination.

The cyclone separator 52 is provided for collecting the coarse dust C containing the concentrated onium salt or the like as described above, and the recovered coarse powder dust C is supplied from the inlet 41a together with the inorganic substance S4. Rotating kiln 41. Instead of the cyclone separator 52, other forms of classifiers can also be used.

The bag filter 53 is provided for the purpose of pulverizing the dust of the barium salt or the acid gas contained in the exhaust gas G3 of the cyclone 52. F recycling. Instead of the bag filter 53, other types of dust collectors can also be used. In addition, the bag filter may be arranged in two rows, and the bag filter in the previous stage collects the dust F of the fine powder absorbing the barium salt, and then adds the exhaust gas treating agent for removing the acid gas in the bag filter in the latter stage. To recover dust that is contaminated with acid gases.

The denitration column 54 is provided for decomposing and removing NOx in the smoldering exhaust gas G4 passing through the bag filter 53 by using a catalyst or the like. The denitration column 54 is, for example, a honeycomb shape, and can be configured in a small form even when a large amount of combustion exhaust gas is processed. Further, not only the NOx is decomposed and removed, but also the desulfurization function for absorbing and removing SOx may be added.

The decontamination product classification device 6 is disposed in the subsequent stage of the calcination device 4, classifies the clinker (decontamination product) P1 which can be used in the form of geomaterials, and further adds the mixed insoluble material Q; The classifier 61 and the insoluble material addition mixer 62 are comprised.

The classifier 61 is provided for the purpose of adjusting the size of the decontamination product P1 to a particle size suitable for a cement admixture, a geomaterial, or the like (hereinafter simply referred to as "geomaterial or the like") P3. Here, the particle size of the decontamination product P1 differs depending on the firing conditions such as the firing temperature and the residence time of the firing device 4. The particle size of the decontamination product P1 can be omitted even if it is not classified, and is suitable for the particle size of P3 such as geotechnical materials. Further, in the case where it is necessary to classify, it is suitable for P3 such as geotechnical materials, and the pulverizer may be disposed in the front stage of the classifier 61, or the classifier may be combined with the pulverizer in plural.

The insoluble material addition mixer 62 is disposed in the subsequent stage of the classifier 61 and is provided for the following purpose: in the classification of the decontamination product In the case where P2 is eluted with heavy metals, hexavalent chromium, fluorine or the like, the insoluble material Q is added to the decontamination product P2 from the viewpoint of preventing the occurrence thereof. As the insoluble material Q, at least one selected from the group consisting of a reducing agent and a sorbent can be used. Examples of the reducing agent include compounds such as sulfites such as sodium sulfite, iron (II) sulfates, iron (II) salts such as iron (II), sodium thiosulfate, and iron powder. Examples of the sorbent include zeolite, clay minerals, layered double hydroxides such as hydrotalcite compounds such as Mg-Al and Mg-Fe, and Ca-Al hydroxides; ettringite and monosulfuric acid; a Ca-Al compound such as a salt, a hydroxide containing iron oxide (hematite) or cerium oxide; a magnesium compound such as magnesium hydroxide, light burnt magnesium, fired dolomite or magnesia; iron sulfide and iron powder An iron compound such as Schwertmannite or FeOOH; a mixture of one or more of cerium oxide, aluminum oxide, and iron oxide; or a fired product, a cerium, or a rare earth element. These reducing agents and sorbent agents may be used alone or in combination of two or more. Here, the amount of elution of the heavy metal or the like from the decontamination product P2 differs depending on the content and form of the heavy metal or the like contained in the organic substance O3 and the inorganic substance S4 supplied to the firing device 4. Therefore, when the amount of elution of heavy metals or the like is lower than the standard of the geomaterial or the like, it may be omitted.

Next, the operation of the radioactive cesium removing apparatus 1 having the above configuration will be described with reference to Fig. 1 .

After the received organic substance O1 is dried in the dryer 21, the dried organic substance O2 is introduced into the pulverizer 22, and pulverized into a desired size.

On the other hand, after the modified material T is added to the received inorganic substance S1 and reformed by the reformer 31, the modified inorganic substance S2 is supplied to the dryer 32 to be dried, and the dried inorganic substance is further introduced into the pulverizer 33. S3, pulverized to a desired size.

The dried and pulverized organic substance O3 and the fossil fuel F1 are blown into the rotary kiln 41 from the burner 41b and burned, and the modified and dried pulverized inorganic substance S4 and the calcium source as the reaction accelerator A are supplied from the input port 41a. And burned. By supplying the reaction accelerator A, the alkalinity of the burned material can be increased, and the generation of the liquid phase in the firing process can be suppressed, and the radioactive cesium contained in the organic substance O3 and the inorganic substance S4 can be efficiently volatilized.

As the calcium source, calcium carbonate, quicklime, slaked lime, limestone, dolomite, blast furnace slag, or the like can be used, and one type of these groups may be used alone or two or more types may be used in combination. Among them, calcium carbonate is preferably decomposed into calcium oxide (CaO) and carbon dioxide (CO ₂ ) by decarburization by sensible heat in the rotary kiln 41.

The radioactive cesium contained in the inorganic substance S4 and the organic substance O3 is volatilized in the rotary kiln 41, and is introduced into the cooling tower 51 in a state of being contained in the exhaust gas G1.

In the cooling tower 51, the exhaust gas G1 is rapidly cooled by the water sprayed from the water diffusing device 51a (or the cooling air introduced into the cooling tower, or a mixture thereof), and the exhaust gas G1 is contained therein. The crucible is solid and is attached to the dust.

Next, the exhaust gas G2 from the cooling tower 51 containing the phosphonium salt is introduced into the cyclone 52, and the coarse dust C contained in the exhaust gas G2 is recovered. Has The recovered coarse dust C is sent back to the rotary kiln 41. Although the coarse powder dust C contains a cerium salt, since it has a low content rate, it is sent back to the rotary kiln 41 to re-evaporate and recover the hydrazine.

The exhaust gas G3 of the cyclone 52 is introduced into the bag filter 53, and the fine dust F containing the barium salt in a high ratio is recovered. The collected fine dust F is further subjected to volume reduction treatment by washing with water, suction, compression, etc., and then stored in a cement container in a sealed state and transported to an intermediate storage facility or a final disposal site. Further, the dust that has absorbed the acid gas or the like contained in the exhaust gas G3 is also recovered by the bag filter 53.

The exhaust gas G4 of the bag filter 53 is introduced into the denitration column 54, the NOx contained in the exhaust gas G4 is decomposed and removed, and the exhaust gas G5 of the purified denitration tower 54 is discharged from the chimney 55 to the atmosphere.

On the other hand, the inorganic substance S4 charged in the rotary kiln 41 is burned by the combustion heat of the fossil fuel F1 and the organic substance O3 blown from the burner 41b in the rotary kiln 41, and the radioactive cesium is volatilized and removed. The clinker cooler 42 is used for cooling to produce a clinker (decontamination product) P1 which can be used as a geotextile or the like. The high-temperature exhaust gas H of the clinker cooler 42 is used as a heat source of the organic dryer 21 or the inorganic dryer 32.

The decontamination product P1 is classified into a particle size which can be used as a geotechnical material or the like by the classifier 61, and further, the insoluble material Q is added to the decontamination product P2 by the insoluble material addition mixer 62. As a method of mixing the decontamination product P2 and the insoluble material Q, for example, the decontamination product P2 is mixed with the powdery insoluble material Q; the insoluble material Q is previously Mixing with water to form a slurry or an aqueous solution (hereinafter also referred to as "slurry or the like"), mixing the decontamination product P2 with a slurry or the like; spraying the slurry to the decontamination product P2; or immersing the decontamination product P2 in the slurry The way to wait.

As described above, according to the present embodiment, radioactive cesium can be efficiently and efficiently removed from the radioactive cesium-containing organic substance O1 and the inorganic substance S1, and these can be utilized as fuel and raw materials, and can be utilized as cement. Decontamination product P3 of mixed materials and geotechnical materials.

Further, in the above-described embodiment, the cyclone separator 52 is provided in the front stage of the bag filter 53, and the coarse dust C is separated and sent back to the rotary kiln 41. However, all the dust contained in the exhaust gas G2 of the cooling tower 51 can be recovered. After the comprehensive reduction of the recovered dust is carried out, it is transported to an intermediate storage facility or a final disposal site.

In addition, the inorganic substance S4 and the reaction accelerator A are mixed from the inlet port 41a and supplied to the rotary kiln 41, but they may be separately supplied. Further, the input position is not limited to the input port 41a as long as it is input from the kiln rear portion in the rotary kiln 41. Further, the organic substance O3 is only required to be supplied to the front portion of the kiln in the rotary kiln 41, and the input position is not limited to the burner 41b.

1‧‧‧ Radioactive cesium removal device

2‧‧‧organic material drying and pulverizing device

3‧‧‧Inorganic modified dry pulverizing device

4‧‧‧Burning device

5‧‧‧Decontamination system

6‧‧‧Decontamination product classification device

21, 32‧‧‧ Dryer

22, 33‧‧‧ pulverizer

31‧‧‧Changer

41‧‧‧Rotary kiln

41a‧‧‧Inorganic input

41b‧‧‧burner

42‧‧‧Clinker cooler

51‧‧‧Cooling tower

51a‧‧‧Dispersion device

52‧‧‧Cyclone separator

53‧‧‧ bag filter

54‧‧‧Denitrification tower

55‧‧‧ chimney

61‧‧‧ classifier

62‧‧‧Insoluble metal addition mixer

A‧‧‧Reaction accelerator (calcium source)

C‧‧‧ coarse dust

F‧‧‧Micronized dust

O1, O2, O3‧‧‧ (containing radioactive cesium) organic matter

F1‧‧‧ fossil fuel

G1, G2, G3, G4, G5‧‧‧ exhaust

H‧‧‧Exhaust gas from clinker cooler

P1‧‧‧Clinker (decontamination product)

P2‧‧‧Decontamination products

P3‧‧‧Geotechnical materials, etc. (decontamination products)

Q‧‧‧Insoluble materials

S1, S2, S3, S4‧‧‧ (containing radioactive cesium) inorganic substances

T‧‧‧Changed material

Claims (8)

A radioactive cesium removal device comprising: a rotary kiln; an organic material supply means for supplying an organic substance contaminated with radioactive cesium to a kiln of the rotary kiln; and a reforming machine for adding a calcium source to the inorganic substance contaminated with radioactive cesium a modifier; an inorganic material supply means for supplying the modified inorganic substance to the kiln of the rotary kiln; and a reaction promoter supply means for supplying the calcium source as a reaction accelerator to the kiln of the rotary kiln; and a recovery device In the rotary kiln, the organic substance is recovered from the enthalpy which is volatilized when the modified inorganic substance is fired. The apparatus for removing radioactive cesium according to claim 1, comprising: a dry pulverizing apparatus for drying and pulverizing the organic substance before the organic substance contaminated with the radioactive cesium is introduced into the rotary kiln. The apparatus for removing radioactive cesium according to claim 1 or 2, further comprising a reforming machine for modifying the inorganic substance before the inorganic substance contaminated with the radioactive cesium is introduced into the rotary kiln. The apparatus for removing radioactive cesium according to claim 1 or 2, further comprising: a dry pulverizer for drying and pulverizing the inorganic substance before the inorganic substance contaminated with the radioactive cesium is introduced into the rotary kiln. The apparatus for removing radioactive cesium according to claim 1, wherein the foregoing recovery device It is a cooling tower that cools the exhaust gas of the rotary kiln, and a dust collector that collects dust in the exhaust gas of the cooling tower. The apparatus for removing radioactive cesium according to claim 5, wherein in the preceding stage of the dust collector, a classifier for separating coarse dust in the exhaust of the cooling tower is provided, and the coarse dust separated by the classifier is sent back. The aforementioned rotary kiln. The apparatus for removing radioactive cesium according to claim 1, wherein when the organic substance contaminated with the radioactive cesium is fired together with the inorganic substance contaminated with the radioactive cesium, a calcium source is added to the rotary kiln. The apparatus for removing radioactive cesium according to claim 1, comprising a classifier for classifying the decontamination product generated after volatilization and removal of the radioactive cesium in the rotary kiln; and adding a mixer to the insoluble material for further decontamination The product is added to the mixed insoluble material.